Chuck



July-7, 1931.

A. J. LEWIS CHUCK Filed Nov. 2, 192s nl@ x E n ,i

` :.:45 support.

Patented July 7, 1931 ESD ArEfN-T `@1er-lucla:

ARTHUR J.,LEWIS, "OF STRAT'FR'D,.',CONNECTICUT -ASSIGNOR JTO {THE BAIR-D MA- CHINE COMPANY, F BR'IDGEPORT,CONNECTICUT, VA CORPORATION .0F CONNECTICUTy CHUCK :ApplicationleiNovember 2, 19.28. SeriaLNo. 316,662.

il). spindle machine. j

It-is also an` object .of "the -invention to y Y provide rimprovedineans for .operating the ,.jaWs of the chuckin Whichthere is .positive movement thereof in both directions .to

i .clamp the-worker release it.

It is another object; of the kinvention to ,provide a construction in which a comparatively small Ytorce `may providefa large clamping .force at `the ,j aWs.

With. thegforegoing, and other. ,ob jectsy in View, the inventio-n consists in ,certainnovel `features of construction,y combinations Tand arrangements of parts. as Willbe moreftully described in connection .Withgthe.accompany- K ing drawings. `In thesedrawings,

chuck involving` my improved Aconstruction and, a portion of. a vrotatable turret in AWhich position.

`FigqQis an v,end Iview,lookingffroln the right offFig. 1.=With a Wallbrokenawayfto more clearlyshovv the construction.

e5 Eig-..3 is asectionsimilarto 1 shoW- sleeves 32 and 33 rmay be clamped against .ing the 4jaws in open position. Fig..4is a transverse. sectionsubstantiall on line 4 4 of Fig. 1, and

Fig. 5 is. adetail section substantially on i401 linee-f5 of Fg..2.

.In the drawings .10,indicatesa rotatable turret `Vwhich. may` carry a plurality of spindles, kas indicated in my applica-mon above, specified, .or .it may be aA stationary "Mounted in :this supportare bearingy bushings/11, and 124 for my improved chuck Which includes a hollow rotatable Vspindle 13 'mounted in.tliese bushings androtated by. any suitable` means, fsuclias a l'clutch j avv, .notshownf adapted tocooperate with a vlig. 1 is aqlongitudinalsecton through a j.

clutch jaw 14 mounted on the spindle and having clutch teeth 15. The spindle has at lone end a head livliicli has radial guide- Ways for one or more chuck jaws 17 In the present instance, tWo of these jaWsare kshovvn movingl in opposite directions in a transverse guidevvay 18 in the head. The side Walls of this guideway have channels 19 in which ribs 2O on the jaws are adapted to slide and which cooperate to retain the `javvs in the head.

Each .jaw is connected to a pivoted lever 21 located back of the jaw inthe head, and this lever has atongue @extending into a recess 123 in the rear Wall of its jaw. The

other end of the lever is connectedby a link 24 to an operating bl0ck25 mounted for reciprocating movements longitudinally of the axis of the spindle, vthe linksQAL being pivoted to the levers andthe block 25 by the pivot pins k26 and?? respectively. The

levers andthe block are preferably `forked so as to straddle the links. rlhe levers are mounted on transverse pivoty ,pins orfstuds 28 Which have bearings. in the head and the lever, the bearing 29 in the lever being eccentric to those in the head so 4that on turning` movementsl of the pin the posit-ion oi' the lever may be adjusted. 'The pin may have a circumferential groove 3() in which a transverse clamping screw 31 extends and this screw is threaded at one side of the pin in a sleeveBQ, While the sleeve 83 is slidable on the screw 31 on the opposite side of the pivot pin, and by turning the screw 31 the oppositesides of thepin to prevent its turning inthe-head after ithas been adjusted. The cooperation of `the screw 31 and the groove SO-retainthepivot pin inthe head.

-The head of the pin Amay be provided with a scale'l'to indicate various positions of The block 25 is mounted Jfor slidinginovements longitudinally of the spindle. It maj,7 be guided in the bushing 36 and maybe `urther guided by keys'37 mountedin the ing longitudinally of the spindle and secured at one end to the block by any suitable means, such as a screw thread 39 and a pin 40. At its opposite end the rod 38 is slidable in the spindle and is accessible, as shown at 41, for operation by any suitable means, such as a stud 42, which may be operated by a cam or other suitable means as described in my application above mentioned. The rod 38 is embraced by a spring 43 which engages a washer 44 at one end secured. to the rod while at its other end the spring rests against a stop bushing 46 threaded in the spindle. The rod 38 slides in the bushing 46 but is splined thereto by a key 47 which will allow sliding movement of the rod but will prevent its turning in thebusliing. Therefore, rotation of the rod will adjust the bushing 4G longitudinally of the spindle to vary the tension of the spring 43. The collar or washer 44 is secured to the rod 38. and therefore, spring 43 tends to| force this rod to the left or to the position of Fig. 1, the shoulder limiting the movement in that direction. This movement of the rod carries with it the block 25 which will straighten out the links 24 and operate the levers 21 to force the jaws 17 inwardly or toward each other and clamp the work 48. l l

It will be apparent from an inspection of Fig. 1 that the elements are sc proportioned and arranged as to have the'jaws clamped just before the links 24 come into a straight line. This arrangement gives the effect or a toggle action which gives an immense clamping pressure on the work with a relatively small pressure on the block 25. The

adjustable pivot pins 28 for the aws permit adjustment of the aws and their operating levers 21 for variations in the work and to give the maximum clamping. effect, which, as indicated above, is just before the links come into a straight line. It will also be apparent that as the links 24 are nearly in a straight line, outward pressure on the jaws 17 cannot shift the block 25, and therefore, no locking device is required to lock the aws in the clamped position. Another important feature of the eccentric mounting for the levers 21 is that by rotating the pins 28 the lugs 22 on the levers may be withdrawn from the recesses 23 in the jaws permitting the jaws to b e slid from the head.

To release the work all that is necessary is to push inwardly on the end 41 of the rod 38, as indicated in Fig. 3, by the member 42. This forces the block 25 to the right to Ithe position shown, and by shifting links 24 will manipulate the levers 21 to separate the jaws 17. It will also be apparent from this arrangement that in clamping the jaws, that is, moving them from the position of Fig. 3 to that of Fig. 1, a given movement of Ythe block 25 gives the greatest amount of movement to the jaws during the first part of their movement toward clamping position when the least force is required, and the smallest movement of the jaws for a given movement of the block is secured at the time the jaws are clamped on the work, or the position of Fig. 1, so that a relatively small force on the block 25 will Igive a large clamping force. This action is due to the inclined arrangement of the links 2,4 at the beginning of the inward movement of the jaws, as shown in Fig. 3, and the great clamping eillect is secured by the toggle action when these-links approach alignment as indicated in Fig. 1.

It will be apparent that with this construction and arrangement very few elements are required, and therefore, the construction is a very simple one, and an immense clamping pressure may be applied to the jaws with a relatively small operating force. As the links 24 are in substantial alignment when the jaws are clamped on the Work there can be no reverse movement of the operating block 25 by pressure from the jaws. Therefore, no locking means is required. It will, of course, be obvious that other means than the spring 43 and the element 42 may be used for operating rod 38 and block 25 for manipulating the jaws of the chuck. It will also be apparent that there is positive operation of the jaws in both directions. Although I have' shown a chuck involving two jaws this same mechanism may be used in a chuck having one or three or more movable jaws.

Having thus set'forth the nature of my invention, what I claim is:

1. In a chuck, a circular head having radial guideways in theY face thereof vand a chamber communicating with said guideways, jaws mounted to slide in said guideways, levers pivotally mounted in the chainber and enclosed by the walls thereof, means for connecting the levers to the jaws, a hollow rotatable spindle carrying the hea-d, a

' block mounted to slide longitudinally in the spindle, links pivoted to the block and the levers to form a toggle therewith, a longitudinal rod in the spindle connected to the block for shifting it, and a spring in the spindle tending to shift the rod to close the jaws.

2. In a chuck, a circular head having radial guideways in the face thereof and a' chamber communicating with said guideways, jaws mounted to slide in said guideways and having recesses in their inner walls, levers pivotally mounted in the chamber and enclosed by the'walls thereof and each havingY a lug to enter `the recess in one of the jaws, a hollow rotatable spindle carrying the head, a longitudinally slidable block enclosed by the spindle and head, links pivoted to the block and the levers to form a toggle therewith, means within the spindle for shifting therblock to open the jaws, and a spring within the spindle tending to shift the block to close the jaws.

3.' In a chuck, a circular head having a radial slot, a jaw mounted for sliding movements in the slot and having a recess in a side wall thereof, a lever having a lug projecting into said recess to shift the jaw, a pivot pin having bearings so as to turn in the support and also having an eccentric bearing for the lever offset sufliciently from the first bearings so as to remove the lug from the recess when turned to its extreme position and permit withdrawal of the jaw from the head, means for securing the pivot pin in different positions, a movable block, and an operating link pivoted to the block and the lever.

4. In a chuck, a rotatable support, a jaw mounted for radial movement in the support, a lever connected to the jaw, a pivot pin mounted to turn in the support and having an eccentric bearing for the lever, means whereby the pin may be turned to adjust the position of the lever, means for operating the lever to shift the block, said pin having a circumferential groove, a clamping screw extending transversely in said groove, sleeves on the screw on opposite sides of the pin, and connections between the screw and the sleeves to clamp them against the pin in the groove to hold the pin in adjusted positions.

In testimony whereof I affix my signature.

ARTHUR J. LEWIS. 

